Composite dental foil and process of making same.



- J. J. KESSL-ER.

COMPOSITE DENTAL FOIL AND PROCESS OF MAKING SAME.

APPLICATION FILED AUG. 7, 1911. 1,008,970.

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Patented N0v.14,191 1.

UNITED STATES PATENT. omen..-

.romr .1, Russian. or sr. Louis,

MISSOURI, ASSIGNOR TO ADOLPEUS G.- .MEIER, OF- ST. LQUIS, MISSOURI. 1

V comrosrrr: DENTAL son. AND rnocnss or MAKING same.

I Specification of Letters Patent. I Patented NOV. 14, 1 91] Application filed August 7; 1911.

Serial No. 642,792.

To all whom it may concern.-

Be it known that I, JOHN J. KEssLER, a citizen of the United States, and residing at St. Louis, State of Missouri, have invented certain new and. useful Improvements in Composite Dental Foil and Procs's of Making the Same, of which the following is a specification.

This invention relates to dental foils which are adapted to be used as toothfilling materials.

Dental filling materials are usually furn'is'hed't-o dentists'in the form of foils, and in use pieces of foil are folded and plugged into the tooth cavity; One .of the chief requirements of such a filling material is co- :hesiveness, for tliep'ieces must 'when plugged into place cohere to form a solid and compact mass The material most generallyused 'is gold, since it possesses great cohesive properties. Due to the fact however that the gold must have a high purity in order to possess this desirable property, the filling is necessarily expensive. One of the disadvantages of, a gold filling is its high;

thermal conductivity which causes discomfort; I 3 Various attempts have been made to sub-f stitute for gold a cheapermaterial but with out success, since few materials possess the desirable cohesive property and at the same; time are suitable for a tooth filling. Among others tin has been tried, but since tin is not cohesive to any great extent, dentists have attempted to use it in combination with gold by placing afoil of tin between two foils of pure gold, cutting the layers into pieces and plugging the same into the tooth. Due to "the fact however that tin lacks the necessary cohesive property it requires from five to six times the length of time to plug. a tooth in order to obtain a coherent and compact filling that is required with gold. This material is therefore impractical on account of: the length; of-timerequired for performing the filling operation, making thegcost of the worknot only excessive but also-causing added discomfort to the patient. While therefore a filling material consisting of a combination of tin and gold is cheaper than go'ldand produces a betterfilling, the total cost of the finished filling is higher.

The object of this invention therefore is I to producea dental foil whinh will possess all the desirable characteristics as to cohesiveness of a in the'tooth will possess all thedesii'ablc properties and characteristics of a gold filling and additional ones. In accordance with this invention a cheap or base metal forms the body of the foil,'and this body is provided with a surface of a cohesive metal like gold, the surface and body metals being united to form a unitary foil ready for use by dentists.

The drawing represents the novel foil forming the subject matter of this invention, Figure. 1 being a view showing'the different component parts of the foil and Fig. 2 being a section.

The process of making this composite 'foil will first be described. A foil of a metal which to form thebody is placed between two tells of ametal which is to form the surfaces and the foils are then united by pressure. 'As to a foil so that sixteen'square inches will weigh from four to eight grains, and pure gold reducedto a ffoil so that sixteen square inches'will weigh from one to four grains,

are used. The 'foils are rolled together'by passing them between r'olls. In" the rolling operatlon the'gold foils are assembled On' paper.' In practice the gold foil as it comes from the gold beaters will be'furnished on a backingof soft paper'and this paper backing can therefore be used.' The tin fo'il'and the gold foils with their paperbackings' are assembledwith the 'tin foil betweenthe gold foils 'and with the paper backings 'on the outside, and'the assembled foils and paper are then passed through the rolls several times. 'Thismethod greatly facilitates the assembling operation and pr'otects the foils, since the gold foils especially-are very thin.

. The pressure of the rolls will be transmitted an example, pure tin reduced through the paper and this pressure will be distributed ln'ore'evenly and over a greater area than if the foils were passed bare through the rolls. Thistherefore obpiates damage to the foils. The first operation is -what-may be termed the assembling operation in which the foils are assembled, the air driven out from between the foils, and the foils partiallyv joined or united- In order to completetlie operation the paper backings are removedand'the partially united foils arethen passed bare between smooth rolls- The rolls-are run at acomparatively low speed and the pressure is such that it kept clean and dry, and care must-be taken I twenty per cent. or even lower. The layers of tin is very much lower than that of gol will not exceed the point at which the foils will be elongated, for. beyond that point the foils will wrinkle. The pressure is however sufficient to cause thesurfac'e foils to unite with the bod foil to form a unitary foil. In order to tain a perfect union the surfaces of both the tin and the gold should be itself than gold. A mixture'of gold and tin I in a tooth undergoes some p chemical change whereby the entire mass 0 gold and tin is changed into a structure re sembling a tooth structure. In making; this change the filling expands slightly,"-

and cavities in the tooth.

- In the. specification certain proportions I have been described and the steps of the process enumerated in a defined manner. It will be understood however thatthese proportions and the series of steps as well as the specific metals have been used rather as illustrative, since various metals and proportions may be used and the strict sequence of steps in the process deviated from within the scope of the appended claims without departing from the spirit ofthis invention.

Having thus described the invention what is claimed is:

1., A composite dental foil comprising a body of tin and a plating of gold united by pressure.

2. A composite dental foil comprising tin plated with gold. f

3. A fiberlcss dental foil comprising tin plated with gold.

4. The process of making composite dental foils comprising tin and gold, which consists in placinga tin 'foil between two gold foils and then uniting them together by pressure. a

5. The process of making-composite dental foils which consists in applying a surface foil to a body foil and breaking up the fiber of the composite foil.

6. The process of making composite dental foils comprising body and surface foils, consisting in uniting the body and surface foils and rolling the composite foil between papers to break up the fiber. T u

- 7. The process of making composite dental foils comprising a tin body foil and gold surface foils, consisting in uniting the foils zfind breaking up the fiber of the composite o1 i In testimony whereof I aflix my signature in presence of two witnesses.

JOHN J. KESSLEB.

that no oxidation. of the tin occurs during the operation. The product as it comes from the smooth rolls will have a smooth surface and will have a grain or fiber which may cause the foil to be stiff. Now it is desirable that a dental foil be soft and pliable in order that it maybe easily plugged into the crevices of thetooth. In order therefore to reduce the foil to'such a pliable state it is passed several times through rolls with rough paper. This will break up the fiber and make the foil soft and-pliable and give it a mat or semi-mat surface finish and even give it a mark taken from the paper.

The finished product will be a composite foil having a body of 'tin and surfaces of gold. Since the gold can be beat out very thin, the percentage of. gold in the composite foil can be made very small-as small as of this composite foil will be united together into a unitary foil and can thus be used as anordinary gold foil. The resultantfoil having surfaces of pure gold will be cohesive the same as a pure gold foil, although the percentage of gold'may be comparatively small. It can therefore be plugged into a tooth to make a compact and coherent filling with practically the same amount of labor as 1s required when pure gold is us d. The gold and tincombination is not in this case in the form of separate loose layers which layers must be plugged and joined together in the tooth, but the tin body and the gold surfaces are united together to form a coherent structure. Not only is this filling material much cheaper than a pure gold filling, but it is better and ossesses more desirable properties and characteristics. The thermal conductivity and therefore the resultant product will have a lower conductivity, thus causing less f VVitnessesz' discomfort. Tin and therefore this prod- CHAS. 'A. BECKER, H. M. HnRsn'L.

uct is more tolerant to the tooth structure ysical and 5:5" 7

driving it into and filling'the smaller pores 60 1 f 

